Abstract

Atmospheric CO2 concentration increased throughout the last century and is expected to continue increasing in the future. Studies on the effects of elevated CO2 concentration on insect herbivores have primarily focused on perennial trees, but relatively little is understood about the effects of elevated CO2 concentration on crop plants and subsequently on their insect herbivores. This study assayed the effects of elevated CO2 concentration on tomato plants growth and the tobacco caterpillar Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) fed on tomato plants. Our results demonstrated that the growth parameter and nutritional quality of tomato plants were altered by elevated CO2 concentration; the tomato plants showed an increase in biomass and defense protein activities and reduced leaf nitrogen content and changes in secondary compound contents. Furthermore, S. litura larvae, which fed on tomato plants grown at elevated CO2 concentration, had considerably decreased growth performance. In summary, elevated CO2 concentration can strongly influence interactions between plants and insects and could have critical impacts on agro ecosystems.